A technology of a printer which performs printing using a plate is applied not only to printing of printed matters but also to various fields. In this printer, since a printing atmosphere such as a temperature or humidity influences a print quality, a technology which adjusts the printing atmosphere is suggested so as to obtain a predetermined print quality.
For example, PTL 1 discloses a technology which forms a light emitting layer on a substrate by flexographic printing using a letterpress (printing plate). In this technology, the light emitting layer is formed by printing ink for the light emitting layer, in which polymer organic light-emitting matters are dissolved and dispersed in a solvent, on the substrate. However, the film thickness of ink varies due to the atmosphere of a solvent gas. Accordingly, a technology is suggested in which the solvent gas for ink is supplied to a closed space in which the periphery of the printing plate is covered with a plate cover so as to adjust the atmosphere of the solvent gas.
In addition, since moisture contents influence ink transcription or image formation properties in a case where printing is performed by water based ink in offset printing using lithography, PTL 2 discloses a technology which covers a portion reaching the transfer from ink around a plate cylinder or a blanket cylinder using a cover and adjusts the internal temperature.
Moreover, PTL 3 discloses a technology in which a plate surface portion from inking to transfer is sealed by a cover and concentration of a solvent for ink on the plate surface is constantly maintained so as to obtain a predetermined printing density in gravure printing which uses an intaglio plate.